Dental Implants In Contemporary Restorative Dentistry

It is a well-established principle of Dentistry, that unless there is no other option, teeth should not be extracted. But, except for teeth removed for orthodontic reasons, if a tooth needs to be extracted, it should be replaced – one way or another – as soon as possible. Also, most of the time, missing teeth should be replaced, as that is in the patient’s best long-term interest.  This is especially true for every tooth from the first molar inclusive, forward.

Classical dentistry, as practiced for ages, was to replace a missing tooth by means of a fixed-bridge: the bridge was supported by the teeth adjacent to the space created by the missing tooth – what we call the abutment teeth. Usually, the bridge was secured to the abutment teeth by preparing them for full crowns.Replacement of missing teeth by means of a removable partial denture (sometimes also called a removable bridge) has been another option, dependent upon the suitability of abutment teeth to support such a restoration.

With improvements in dental materials and techniques, fixed bridges evolved from full-crown coverage on the abutments, to bonded “wings” on the abutments, etc.

It is now possible to replace missing teeth without involving abutment teeth. This is accomplished by placing dental implants into the site of a missing tooth. The implant site is prepared to receive the implant, which resembles a screw that is turned into the jawbone and secured there. The implant has an internal socket and a screw into which a post can be positioned, and a crown cemented on top of the post. In order for an implant to be a consideration, however, there must first be sufficient bone to receive it. And, the patient’s medical condition is also crucial: diabetics and smokers are not usually the best candidates for implants.

Some of the advantages of an implant over other fixed restorations are:

1. They are conservative of adjacent natural teeth: no tooth preparation is required as there are no abutment teeth. It is important to remember that once a tooth is “prepared” in any way, no matter how slight, that tooth is never the same as it was, and it remains changed forever.
2. The risks to abutment teeth from any kind of preparation include: pulpal trauma and infection, which could require root canal treatment or extraction. When an implant is placed, these risks to the abutment teeth are not an issue.
3. Bone is maintained around the functioning implant, preventing the normal loss of the bone in the “empty” site where the tooth once was.
4. The work required to produce the final restoration is accomplished with less trauma to the patient, in less time, and more comfortably.
5. The cost of a single tooth implant is almost the same as the cost of a single tooth replacement fixed-bridge.
6. The theoretical life-span of a dental implant is comparable to the lifespan of an equivalent fixed-bridge. But, it is important to know that it is unrealistic to expect an implant to last forever. Oral hygiene, and other factors can influence the longevity of any implant.

There are situations in which it makes more sense to extract a tooth that is seriously compromised and replace it with an implant – either immediately, or within several months’ time – rather than subject that tooth – and the patient – to root canal treatment, post-core, and crown.

The bottom line is: Implants must be seen as an integral part of the restorative continuum for adults in contemporary restorative dentistry.

If a tooth needs to be extracted, and if an implant is being considered, it may be advisable to try to maintain the maximum amount of bone available for the implant, by placing bone-regenerative materials into the socket immediately after extraction. This helps to prevent the rapid bone-loss that usually follows the extraction of a tooth. And, it helps to ensure that the bone that regenerates will be able to receive and support the implant.

There are various types of bone-regenerative materials, and the waiting period following their placement, until an implant can be installed, varies from 3 to 6 months.

The major downside concerning implants is that the treatment is not as quickly-completed as a fixed bridge or a partial denture. Under ideal conditions, between 5 – 6 months is the minimum time between the placement of the implant and the fabrication and delivery of the restoration. If bone regenerative materials have been placed, it is necessary to add an additional 3 to 6 months before the implant can even be installed.